본 연구는 체내, 체외 소 배반포기 배의 GMP vitrification 후 활력도의 비교와 한우 수정란을 몽골 소에 수정란이식 후 산자생산 가능성을 조사하고자 실시하였다. 한우 수정란은 체외수정란 또는 과배란처리에 의한 체내수정란을 생산하여 GMP vitrification 방법으로 동결 후 몽고로 수송하였다. 수란우는 CIDR과 처리에 의하여 동기화를 유도하였다 체내수정란생산을 위하여 7두를 과배란처리하였다. 총 64개의 배반포기를 회수하였다. (pe

As model waterborne acrylic coatings, mono-dispersed poly(butyl acrylate-methyl methacrylate) copolymer latexes of random copolymer and core/shell type graft copolymer were prepared by seeded multi-staged emulsion polymerization with particle size of 180~200 nm using semi-batch type process. Sodium lauryl sulfate and potassium persulfate were used as an emulsifier and an initiator, respectively. The effect of particle texture including core/shell phase ratio, glass transition temperature and crosslinking density, and film forming temperature on the film formation and final properties of film was investigated using SEM, AFM, and UV in this study. The film formation behavior of model latex was traced simultaneously by the weight loss measurement and by the change of tensile properties and UV transmittance during the entire course of film formation. It was found that the increased glass transition temperature and higher crosslinking degree of latex resulted in the delay of the onset of coalescence of particles by interdiffusion during film forming process. This can be explained qualitatively in terms of diffusion rate of polymer chains. However, the change of weight loss during film formation was insensitive to discern each film forming stages-I, II and III.

4D carbon fiber preforms were manufactured by weaving method and their carbon fiber volume fractions were 50% and 60%. In order to form carbon matrix on the preform, coal tar pitch was used for matrix precursor and high density carbon/carbon composites were obtained by high densification process. In this process, manufacture of high density composites was more effective according to pressure increasement. When densificating the preform of 60% fiber volume fraction with 900 bar, density of the composites reached at 1.90 g/cm3 after three times processing. Degree of pressure in the densification process controls macro pore but it can not affect micro pore. During the carbonization process, micro pore of the preform were filled fully by once or twice densification processing. But micro pore were not filled easily in the repeating process. Therefore, over three times densification processing is the filling micro pore.

Plastic deformation was observed by TEM around the intragranular SiC particles in the matrix for nanocomposite system. The dislocations are generated at selected planes and there is a tendency for the dislocations to form a subgrain boundary structure with low-angel grain boundaries and networks. In this study, dislocation generated in the matrix during cooling down from sintering temperatures by the highly localized thermal stresses within and/or around SiC particles caused from the thermal expansion mismatch between matrix and SiC particle was observed. In monolithic and microcomposite system. These phenomena is closely related to the plastic relaxation of the elastic stress and strain energy associated with both thermal misfitting inclusions and creep behaviors. The plastic relaxation behavior was explained by combination of yield stress and internal stress.

It is reported about the recent developments of powder metallurgy technologies in Japan. In this several years, we cannot make no progress in the amount of powder metallurgy parts production. In order to expand the markets, it is necessary to understand the market needs, and promote technical developments to satisfy the needs which include Cost Reduction, Weight Reduction, High Performance and Environmental Friendliness. The key words of developments to meet these needs are as follows, High Productivity Net-shape High Strength High Machinability High Wear-resistance Low Friction High Magnetic Properties High Heat Properties Light Weight. It is reported some examples corresponding with every key words.